HYDRA Arithmetic operations within configs

[vriez]

Consider the configuration files:

# dataset.yaml
# @package _group_
  class_name: dataloaders.datasets.COCODataset
  data_dir: ${storage.data_dir}/Docs
  class_labels: [1, 2]
  num_classes: 2

and

# model.yaml
# @package _group_

  module:
    class_name: segmentation.maskrcnn.models.DateOutliner

  top:
    class_name: torchvision.models.detection.mask_rcnn.MaskRCNNPredictor
    params:
      num_classes: ${dataset.num_classes}

Is there a way to add perform arithmetic operations with a paramete. So as to obtain config.model.top.num_classes as 3 (2+1)?

I have tried many variations, but I have not managed to get it to work:

Below are examples that won't work:

  top:
    class_name: torchvision.models.detection.mask_rcnn.MaskRCNNPredictor
    params:
      num_classes: ${dataset.num_classes + 1} 

  top:
    class_name: torchvision.models.detection.mask_rcnn.MaskRCNNPredictor
    params:
      num_classes: ${dataset.num_classes++} 

[omry]

This is not currently supported. There is a feature request in OmegaConf for it.